Similar Datasets
Project description:Occurrence and mechanism of photoaging in mouse back skin
2024-10-15 | GSE279220 | GEO
Project description:YAP-TEAD complex inhibits photoaging via transcriptional regulation of homologous recombination repair in mouse (smal) - lncRNA-seq
| PRJNA1171415 | ENA
Project description:YAP-TEAD complex inhibits photoaging via transcriptional regulation of homologous recombination repair in mouse (smal) - miRNA-seq
| PRJNA1171416 | ENA
Project description:High expression levels of SLFN11 correlate with the sensitivity of human cancer cells to DNA-damaging agents. However, little is known about the underlying mechanism. Here, we show that SLFN11 interacts directly with RPA1 and is recruited to sites of DNA damage in an RPA1-dependent manner. Furthermore, we establish that SLFN11 inhibits checkpoint maintenance and homologous recombination repair by promoting the destabilization of the RPA-ssDNA complex, thereby sensitizing cancer cell lines expressing high endogenous levels of SLFN11 to DNA-damaging agents. Finally, we demonstrate that the RPA1-binding ability of SLFN11 is required for its function in the DNA damage response. Our findings not only provide novel insight into the molecular mechanisms underlying the drug sensitivity of cancer cell lines expressing SLFN11 at high levels, but also suggest that SLFN11 expression can serve as a biomarker to predict responses to DNA-damaging therapeutic agents.
| S-EPMC4718411 | biostudies-literature
Project description:To avoid cell cycle arrest or apoptosis, rapidly proliferating cancer cells have to promote DNA double strand break (DSB) repair to fix replication stress induced DSBs. Therefore, developing drugs blocking homologous recombination (HR) and nonhomologous end joining (NHEJ) - 2 major DSB repair pathways - holds great potential for cancer therapy. Over the last few decades, much attention has been paid to explore drugs targeting DSB repair pathways for cancer therapy. Here, using 2 well-established reporters for analyzing HR and NHEJ efficiency, we found that both HR and NHEJ are elevated in hepatoma cell lines Hep3B and HuH7 compared with normal liver cell lines Chang liver and QSG-7701. Our further study found that Harmine, a natural compound, negatively regulates HR but not NHEJ by interfering Rad51 recruitment, resulting in severe cytotoxicity in hepatoma cells. Furthermore, NHEJ inhibitor Nu7441 markedly sensitizes Hep3B cells to the anti-proliferative effects of Harmine. Taken together, our study suggested that Harmine holds great promise as an oncologic drug and combination of Harmine with a NHEJ inhibitor might be an effective strategy for anti-cancer treatment.
| S-EPMC4846143 | biostudies-literature
Project description:Nuclear lamins are type V intermediate filament proteins. Lamins, including LA, LB1, LB2, and LC, are the major protein components forming the nuclear lamina to support the mechanical stability of the mammalian cell nucleus. Increasing evidence has shown that LA participates in homologous recombination (HR) repair of DNA double-strand breaks (DSBs) . However, the mechanisms underlying this process are incompletely understood. We recently identified the first lamin-binding ligand 1 (LBL1) that directly binds LA and inhibited cancer cell growth. We provided here further mechanistic investigations of LBL1 and revealed that LA interacts with the HR recombinase Rad51 to protect Rad51 from degradation. LBL1 inhibits LA-Rad51 interaction leading to accelerated proteasome-mediated degradation of Rad51, culminating in inhibition of HR repair of DSBs. These results uncover a novel post-translational regulation of Rad51 by LA and suggest that targeting the LA-Rad51 axis may represent a promising strategy to develop cancer therapeutics.
| S-EPMC6161055 | biostudies-literature
Project description:Background: N6-Methyladenosine (m6A) methylation, a common form of RNA modification, play an important role in the pathogenesis of various diseases and in the ontogeny of organisms. Nevertheless, the precise function of m6A methylation in photoaging remains unknown. Objectives: This study aims to investigate the biological role and underlying mechanism of m6A methylation in photoaging. Methods: m6A dot blot, Real-time quantitative PCR (RT-qPCR), western blot and immunohistochemical (IHC) assays were employed to detect the m6A level and specific m6A methylase in ultraviolet ray (UVR)-induced photoaging tissue. The profile of m6A-tagged mRNA was identified by methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq analysis. Finally, we investigated the regulatory mechanism of KIAA1429 by MeRIP-qPCR, RNA knockdown and immunofluorescence assay. Results: m6A levels were increased in photoaging and were closely associated with the upregulation of KIAA1429 expression. 1331 differentially m6A methylated genes were identified in the UVR group compared with the control group, of which 1192 (90%) were hypermethylated. Gene ontology analysis showed that genes with m6A hypermethylation and mRNA downregulation were mainly involved in extracellular matrix metabolism and collagen metabolism-related processes. Furthermore, KIAA1429 knockdown abolished the downregulation of TGF-R and upregulation of MMP1 in UVR-irradiated HDFs. Mechanically, we identified MFAP4 as a target of KIAA1429-mediated m6A modification and KIAA1429 might suppress collagen synthesis through an m6A-MFAP4-mediated process. Conclusions: The increased expression of KIAA1429 hinders collagen synthesis during UVR-induced photoaging, suggesting that KIAA1429 represents a potential candidate for targeted therapy to mitigate UVR-driven photoaging.
2024-07-16 | GSE268348 | GEO
Project description:Purpose: The goal of this study is to analyze the transcriptional pathways regulated by Emsy and Keap1 in subcutaneous mouse lung adenocarcinoma tumors. Methods: Keap1 wild type (KP) or mutant (KPK) cells expressing inducible shEmsy or shCTRL were implanted subcutaneously into the flanks of 6- to 8-week-old female syngeneic mice. Once tumors were measurable mice were treated with doxycycline to induce the shRNA expression. Knock down efficiency has been evaluated by western blot (using specific antibody for Emsy) and qPCR (using specific oligos for Emsy). Results: The transcriptomic analysis helps us to support our finding that Keap1-null tumors are characterized by suppression of the IFN response resulting from the stabilization of Emsy.
2021-01-15 | GSE164872 | GEO
Project description:Non-small cell lung cancers (NSCLCs) harboring KEAP1 mutations are characterized by worse overall outcomes and resistance to immunotherapy. Here, we identified a molecular mechanism by which KEAP1 targets EMSY for ubiquitin-mediated degradation to regulate homologous recombination repair (HRR) and anti-tumor immunity. Loss of KEAP1 in NSCLC induces stabilization of EMSY producing a BRCAness phenotype characterized by HRR defects and sensitivity to PARP inhibitors (PARPis). Defective HRR increases genomic instability leading to high tumor mutational burden (TMB), which prompts an innate immune response. Notably, EMSY accumulation also suppresses the type I interferon response and impairs innate immune signaling, fostering cancer immune evasion. Activation of the type I interferon response in the tumor microenvironment using a STING agonist results in the engagement of innate and adaptive immune signaling, impairing the growth of KEAP1-mutant tumors. Our results suggest that targeting the PARP and STING pathways, individually or in combination, represent a novel therapeutic strategy in NSCLC patients harboring alterations in KEAP1.
2022-01-04 | GSE178503 | GEO
Project description:The objective of this study was to investigate the mechanism of sensitivity to methotrexate (MTX) in human choriocarcinoma cells regarding DNA damage response.Two choriocarcinoma cancer cell lines, JAR and JEG-3, were utilized in this study. An MTX-sensitive osteosarcoma cell line MG63, an MTX-resistant epithelial ovarian cancer cell line A2780 and an MTX-resistant cervical adenocarcinoma cell line Hela served as controls. Cell viability assay was carried out to assess MTX sensitivity of cell lines. MTX-induced DNA damage was evaluated by comet assay. Quantitative reverse transcription polymerase chain reaction was used to detect the mRNA levels of BRCA1, BRCA2, RAD51 and RAD52. The protein levels of ?H2AX, RAD 51 and p53 were analyzed by Western blot.Remarkable DNA strand breaks were observed in MTX-sensitive cell lines (JAR, JEG-3 and MG63) but not in MTX-resistant cancer cells (A2780 and Hela) after 48 h of MTX treatment. Only in the choriocarcinoma cells, the expression of homologous recombination (HR) repair gene RAD51 was dramatically suppressed by MTX in a dose- and time-dependent manner, accompanied with the increase in p53.The MTX-induced DNA strand breaks accompanied by deficiencies in HR repair may contribute to the hypersensitivity to chemotherapy in choriocarcinoma.
| S-EPMC5119623 | biostudies-other